Hymer B578 2012 headlamp bulb upgrade.

Gerry77

Gerry77

Joined
Nov 2, 2022
Posts
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Location
Cumbria, UK
Funster No
92,228
MH
Hymer Exsis 504 2014
Exp
Too long
I did this on my previous 2007 504 and really struggled with seized bolts. I read another thread on here “its only three screws” ! Well it isnt that easy on my 2012.
Bonnet drops down not up.
Triangular fixed panel top corners hide top hlamp fixing but fixed by two bolts (easy) however top corner one is bonded to panel but loosened by nut and then twist out of the way to get at headlamp bolt.
To access bottom hlamp bolt needs the grille panel removing
, large self tappers and two very small fiddly screws on centre bracket.
Then unbolt hlamp unit, ease out then change drl and dipped beam bulbs then reassemble.
And repeat otherside.
Top bolt rusty and needed a good soak in penetrating fluid.
So no,not just three screws.
I replaced all fixings with s/steel ones.
Fitted LED drls and osram +200 hlamps.
Easier than my previous one but not 3 screws on mine!
 
Well sets of bulbs changed ( drls and dipped beam)
drls not functioning but dipped beam ok.
The bulbs I removed from the drl position were small 5/6 watt bulbs not the 21watt as I expected. Handbook says PY12V21W ! Presume this is why the new drls are not functioning. Assume I have upset the canbus or could it be a fuse?
 
Gerry77 said:
Well sets of bulbs changed ( drls and dipped beam)
drls not functioning but dipped beam ok.
The bulbs I removed from the drl position were small 5/6 watt bulbs not the 21watt as I expected. Handbook says PY12V21W ! Presume this is why the new drls are not functioning. Assume I have upset the canbus or could it be a fuse?
Click to expand...
The 21 watt ones are correct but they melt the bulb holder probably why they were changed.
 
But they are led ones I have fitted, they are used by all the experts on another forum I used to belong to to reduce the heat of the 21w halogen ones.( to avoid headlamp glass exploding/ failing. The ones that were in were the same as the “ parking light” as described in the handbook but handbook says 21w for the drls.
Handbook says the relay box under drivers seat (RHD) has a fuse B2 signal for daytime running lights etc. Will check that tomorrow.
 
I was referring to the reason the 5 watts had been fitted.
The DRL's are not on the bulb failure circuit so LED's are no problem.

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Ok but any suggestions why they are not working? Do they have a separate fuse ?
 
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Were they working before you changed them?
Check to see it you are getting 12v at the holder.
Are the contacts discoloured so making poor contact?
 
Thanks reply. Contacts very clean and bright but no power to lamp holder. Tried the old bulb and no joy so there is no power getting to the lamps. Sounds as though I need my travelling local vehicle electrician. He is excellent so will give him a shout later.
As I needed to remove the grille below the bonnet I have removed the eml and am repainting it as it has served its purpose of prevent stones attacking the rads.
I replaced the drls on my old Hymer and they worked straight away but the original bulbs were 21W as specified in the handbook.
Is there a way of resetting the canbus to accept these new leds?
 
I have been looking through posts on here for this problem and found reference to a Schaudt AD03 panel which has a fuse for the drls. Cant find reference to its location. Any advice please?
 
Gerry77 said:
I have been looking through posts on here for this problem and found reference to a Schaudt AD03 panel which has a fuse for the drls. Cant find reference to its location. Any advice please?
Click to expand...
Under the passenger seat is a good start loads of relays and a couple Schaudt boxes under mine.
 
Yes looked under drivers seat , found one but a complete jumble of cables, relays and the like. Will vacuum out and do a proper search. Cheers Lenny.
 
Well, after vacuuming up 10years of dust, I removed the plastic seat base covers and found AD01 and B2 labelled as signal for drls 15amp was blown, new fuse and back in business!
What a jumble of gear under the seat! Found the step buzzer what a crap thing they have fitted.
Thanks again but I now know more than I did when I started. You never stop learning even @ 77yo.
 
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